A light emitting diode (LED) has characteristics of low current consumption and long service life. A universalization rate and a market share of LED illumination devices in the field of illumination are becoming higher and higher.
Various LED illumination devices may have matching problems with a traditional lamp holder in practical use. Some problems are structural problems, but mainly are electrical matching problems. When fluorescent lamps are replaced with LED lamps, if all of original fluorescent lamps are entirely replaced, no electrical connection problem exists since the LED lamps are directly connected to mains supply. However, during overall replacement, a ceiling needs to be redrilled for installation, causing certain troubles. When LED light sources replace traditional light sources (such as high intensity discharge (HID) lamps or the fluorescent lamps), since lamp heads are standard lamp heads, no structural problem exists. However, electrical connection has many problems, and improper treatment may even cause electric shock of people, which threatens human life and health. This problem is particularly obvious in LED straight lamps. In real life, a lot of straight fluorescent lamps exist. These lamps will be replaced with the LED straight lamps due to various reasons such as normal damage or energy conservation transformation and the like.
When the LED straight lamps are used to replace the fluorescent lamps, two solutions are mainly used at present The first solution is, an LED driving circuit is placed in a tube lamp of an LED tube lamp. The second solution is, the LED driving circuit is placed outside the tube lamp of the LED tube lamp. A drive built-in LED tube lamp (i.e., the first solution) may have a solution of directly replacing the straight fluorescent lamps and a solution of modifying circuits of the original lamps. Moreover, LED lamp tubes are classified into a single-terminal power supply type and a double-terminal power supply type. It can be seen that, during practical use of the LED lamp tubes, complex situations may exist.
Safer use for a user shall be considered when the LED lamp tubes of different types are used. To solve safety problem, a solution of installing a mechanical switch at the lamp head is commonly adopted in an existing art. When the lamp head is clamped into a lamp holder, the switch is turned on and the LED tube lamp can be used normally. When the lamp head is removed, the switch is turned off. Even if an operator touches the lamp head, electric shock will not occur. However, when the LED tube lamp is installed by the user, the user may press the switch, causing the switch to be in a conduction state, and an electric shock danger may occur. Moreover, this design imposes a structural burden. Since a gap exists when the lamp head contacts the lamp holder directly, the lamp head is installed on the lamp holder actually but the switch is not turned on, causing that the lamp does not illuminate. Moreover, the LED tube lamp is different from the traditional fluorescent lamp. When a lamp wall of the LED lamp tube is damaged, the lamp can be used normally, but electric shock danger may exist when people touch the lamp. Therefore, the existing LED lamp tube has a great potential safety hazard.